DART Hits Asteroid Bull's Eye
On September 26, NASA’s Double Asteroid Redirection Test, DART, crashed into the moon of an asteroid to change its speed and orbit. It was intentional, of course, to prove that it’s possible to use kinetic impactor as a technique to deflect an oncoming object to defend Earth from an oncoming asteroid.
Learn more about DART.
Transcript
00:00:00 [Music] The DART mission is a very difficult mission because we are trying to do something that hasn't been done before. This is the first time we're going to an asteroid that is this small, this dark, and we're actually going to attempt an impact. The DART mission is really something that the whole world can get behind. [Music] We're doing this mission to prove that we can deflect an asteroid if we find one that is on an impact course for Earth.
00:00:35 We are trying to hit an asteroid 163 meters wide. Which is about the size of the Washington Monument, while flying at six kilometers per second which is like going from New York to D.C. in about a minute. There is no chance that this asteroid could ever hit Earth. It's a very small asteroid it's only about the size of a small football stadium. And it's almost 7 million miles away from the earth. That's 28 times the distance between the earth and the moon. There's kind of a limit on how much mass you can launch into space.
00:01:07 You know, rockets are only so big so our spacecraft is only the size of a golf cart. DRACO is the primary instrument on the DART spacecraft. It is the camera that is going to be imaging the Didymos system as we approach. When we first see the asteroid through Draco it's just going to look like a pixel. There's a star tracker on board that takes images of the stars and compares them to a known catalog to determine which way it's pointing in space.
00:01:37 It poses the biggest risk because very very small errors in this measurement can spell the difference between success and failure. And those measurements are going to be fed into the SMART Nav algorithm that's going to be making the autonomous course correction commands that will put us on an intercept course. There is a very small probability that we don't hit the asteroid. Even if we do everything right, our sensors work well, our spacecraft is doing well, we are looking, we are finding the asteroid. Even then, we might still miss. We're trying to teach a computer how to
00:02:12 recognize an object we've never seen before. And the way it does that is by taking pictures of the asteroid and then interpreting where it is in space and guiding itself to it. The spacecraft is controlling itself, SMART Nav is guiding the spacecraft And we have very limited ability to respond in that time. So it has to do it all by itself. And at about two and a half minutes out we cease all maneuvering and we coast until we hit the asteroid. It is going very, very fast towards the asteroid,
00:02:51 traveling at six kilometers per second. 200 times faster than a car on the freeway. So when we hit, all of that mass, all of that momentum pushes the asteroid. Even giving it a small nudge will allow it to change its course. But if we did see an asteroid on track for Earth, this would be enough of a deflection. It's like a bittersweet moment. Yeah, all this hard work just got destroyed, but that was exactly why we put it all together.
00:03:20 Of all the endeavors that we do for space and in space, this is probably one of the ones that one day will be the most important thing that we've ever done. In the future, I hope that DART can teach us what ways work and what ways don't work for planetary defense. Because it is humankind's first demonstration that we have gained the knowledge and the technology to be able to protect the Earth from an asteroid impact. [Music]